# Tear Gas Project

## Background and History

Tear gas isn't truely a gas in itself. The different variations of tear gas are formed from solid or liquids that are turned into an aerosol form. Tear gas is designed to attack pain-sensing nerves. This gas, used as a weapon, was known to have first been used in World War I, but who knows? It could've been around even before that. The common tear gas that is sold to the public is known as chloroacetophenone (or Mace). A milder form of that is pepper spray, which is also sold to the public. It's made of chili pepper and corn oil. Both or these sprays are used as a self defense weapon. Chlorobenzylidenemalononitrile, or CS, is the tear gas that is used in political riots, protests, etc. It is much stronger than Mace, but it doesn't last as long. The main purpose of tear gas is to irritate the victims eyes.
What's Inside: A Can of Tear Gas-WIRED

## Dalton's Law

Dalton's Law says, "The total pressure of a gas mixture equals the sum of the partial pressures that make up the mixture." So basically, if I habe 3 gases added together, the pressure of my final gas is the sum of the pressure of the 3 different gases in that mixture.

## Working Knowledge

From what I understand, Tear gas is composed of many different gases mixed together. Reason being is that the more harsh chemical gases they add to tear gas, the more harmful it is to a persons eyes. When adding these many gasses together, the makers of tear gas have to make sure they don't add so much gas that the pressure over powers the aersol can holding the tear gas. They must find how much pressure the container can hold, and then they must make sure the amounts of gas they add all have pressures that add up to the capacity of the can.

I am now going to set up and example scenario. The calculations in this scenario won't be exact.

Say I want to mix Carbon, Hydrogen, and Nitrogen, and I want to put them in a can that holds 20 L of gas and 25 atm of pressure.

I can add 10 L of Carbon, 5 L of Hydrogen, and 5 L of Nitrogen, but if the corresponding pressure of those gases don't add up to 25 atm, it's back to the drawing boards.

## Works Cited

Howard, Brian Clark. "The Surprising History and Science of Tear Gas." National Geographic. n. page. Web. 20 Apr. 2014. http://news.nationalgeographic.com/news/2013/06/130612-tear-gas-history-science-turkey-protests/.

HowStuffWorks.com, . "What does Tear Gas do?." HowStuffWorks. n. page. Web. 20 Apr. 2014. <http://science.howstuffworks.com/question340.htm>.

"Dalton's Law Partial Pressure." Aquaholic. N.p.. Web. 20 Apr 2014. <http://www.aquaholic.com/gasses/dalton.htm>.